Rick’s class plans to study the effect of eating different breakfast foods on grades in morning classes. Students in the class will be the test subjects for the investigation. Which of the following would most likely make the results of the experiment invalid? Half of the students ride the bus to school, and half ride in cars. Some students eat breakfast two hours before other students do. Some students miss school during the investigation due to illness. All students in the investigation have morning classes in the same subjects.

How did shays' rebellion reveal the need for a revision of the articles of confederation? a) shays' rebellion exposed the weakness of the central government as written in the articles of confederation. b) shays' rebellion strengthened the ideas of the anti-federalists in the need for a strong national government. c) shays' rebellion illustrated the need for organized local government factions to handle situations such as this. d) shays' rebellion encouraged others to rebel and eventually led to the overthrow of the first established government in the united states.